//
// Created by 21577 on 2025/3/2.
//
#include<stdio.h>
#include<math.h>

int main() {
    double d = 300000, p = 6000, r = 0.01;
    double m;
    m = log(p / (p - d * r)) / log(1 + r);
    printf("m=%.1lf\n", m);
    return 0;
}